Offshore wind turbines could do more than provide renewable energy and reduce air pollution. They could also protect cities from the devastating effects of hurricanes, according to a new study in Nature Climate Change.

Hurricanes can cause billions of dollars in damage, and the problem is only getting worse as sea levels rise and developers continue to build along the coasts. Hurricane Sandy, for instance, killed more than 250 people, and the price tag for damages topped $80 billion. People have suggested building sea walls to hold back storm surges, but those are expensive too — on the order of $10 to $29 billion per city.

The study authors wondered if wind turbines off the coasts could weaken hurricanes. “Unlike sea walls, offshore wind turbines could reduce both wind speed and storm surge and would generate electricity year-round,” the team writes.

To test the idea, the researchers ran simulations of Hurricanes Katrina, Isaac, and Sandy. If offshore wind turbines were installed near Cuba and along the Gulf Coast, they estimate, Katrina’s wind speed at a height of 15 meters would have dropped by up to 92 miles per hour. Turbines off the East Coast would have slowed down Sandy’s winds by up to 87 miles per hour. And storm surges for Katrina and Sandy would have dropped by 79% and 34%, respectively.

This strategy could be particularly cost-effective for New Orleans because the city is often hit by hurricanes and wouldn’t require as many turbines as East Coast cities for protection, the authors note. Turbines could cut hurricane damage costs by 0.21 to 0.68 cents per kilowatt-hour in New Orleans and 0.09 to 0.13 cents per kilowatt hour on the East Coast. In addition to holding back storms, the offshore arrays would benefit cities by providing a relatively clean source of energy, cutting pollution from fossil fuel use, and reducing pollution-related health problems. — Roberta Kwok | 27 February 2014